Delinting screen



June 24, 1947. DAVlS, JR

DELINTING SCREEN Filed Ndv. 18, 1945 2 Sheets-Sheet l OUOUU FIG. a

INVENTOR. 'ARGHIBALD H. DAVIS JR.

A TTMNEY June 24, 1947. v s, JR 7 2,422,825

DELINTING SCREEN 4 Filed Nov. 18, 1943 2 Sheets-Sheet 2 FIG.3

IN VEN TOR. ARCHIBALD H. DAVIS JR.

- 48 EMOCALZ/z,

AT ORNEY cylinder while the latter is rotating.

is allowed to reenter the cylinder.

Patented June 24, 1947 UNITED STATES PATENT OFFICE DELINTING SCREEN.

Archibald'H. Davis, J r., Cleveland, Ohio, assignor to American Machineand Metals, Inc., East Moline, Ill., a corporation of DelawareApplication November 18, 1943, Serial No. 510,735

rangement oi the delinting device which forms a part of such dryingtumblers. In drying tumblers such as are used in laundries, the wetclothes are put in a cylinder and dried therein by passing heated airthrough the As the clothes fall through the stream of heated air theyare dried. As the air passes through the clothes it picks up loosefibers, or lint. For reasons of heat economy it is desirable tocirculate the same body of air repeatedly through the cylinders. Eachtime the air recirculates it picks up additional lint. At the end of theoperation cold air is passed through the cylinder to cool the clothes.It is common in the art to provide such drying tumblers, particularly ifrecirculation of the air is to be used, with a device for separating outthe lint which was picked up by the air on its way through the cylinderbefore the air Usually delinting devices take the form of one or severalscreens made of fine wire-mesh through which the air passes. The screenssoon clog up, thus impedingth'e ci culation of the air, necessitatingthe removal of he lint from the screen at short intervals. It has beenfound difiicult to remove the lint from such wire mesh screens, and

cleaning devices of various kinds have been sug- 30 gested for thepurpose of brushing off or other- .wise removing the fibers which havesettled on A the screens. Attempts to l low the lint off by reversingthe air flow through screen have failed,- probably because the lintfibres are often wrapped around the wire of the screens and the aircurrent has twisted the ends of such fibers together.

It is an object of this invention to provide a delinting device whichwill not permit the lint fibres to become tangled around the elements ofthis device.

It is a further object of the invention to provide a delinting deviccomposed of open-ended cells which have substantial depth in thedirection of the air flow. I A

A still further object of theinvention is to provide a delinting deviceof ribbon-shaped material, the edges of the ribbon facing the airstream. s p

Another object of th invention is to provide a delinting device fromwhich lint fibers which have been caught by the device can easily be,blown off.

Another object of the invention is the combination in a drying tumblerof a delinting device which prevents the tangling of lint fibers withthe parts of the device, with means for changing the direction 01' theflow of the air through the delinting device.

Still another object of the invention is to provide a self-cleaningscreen that is cleaned by shifting the dampers m the tumbler from theirrecirculating position to their cooling position.

A still further object of the invention is to, provide, in a dryingtumbler, two alternately functioning air paths, both oi which extendfrom the same side of the fan used for creating the aircirculation'through thetumbler but lead to opposite sides of thedelinting device, the one path leading out to the atmosphere.

Other objects of the invention will appear as the description proceeds,reference being made to the accompanying drawings, in which:

Figured is a. sectional elevation of a drying tumbler, illustrating byway of example one embodiment of the invention:

Figure 2 is a plan view of one form oi. a delinting' deviceaccording tothe invention;

Figure 3'is a section on line 3-3 of Figure 2;

Figures 4 and 5 are plan views of the two modified forms of delintingdevices, and

Figure 6 is a fragmental perspective view of another modified form ofthe delinting device. Referring first to Figure 1, l0 designatesgenerally a housing, comprising a base li, a front wall [2, a rear walll3, and a, top H. Rotatably mounted in housing It! is a cylinder 53having foraminous side walls through which air may pass, said wallsbeing generally made of aheavy, coarse wire mesh. The housing 10 furthercon-' tains a fan or blower l5 adapted to create a forced aircirculation through the tumbler, a heater l6, partition walls l1, l8,I9, 20 and 2|, three dampers '22, 23 and 24, and a delinting devicegenerally indicated at 25. The device 25 may be arranged between thewalls l3 and I1 like a drawer that may he slipped out of the housing l0through an opening in the rear wall i3. 26 denotes air inlet openingsin-the top part H of 22, 23 can be moved together but in oppositedirections.

The dellnting device 25 which forms an essential partiof this inventioncomprises a series of cells 28. The cells 28 have open ends permittingthe passage of air in the direction of the arrows shown in Figure 3 andare of substantial length in this direction. As distinguished from wiremesh screens, the walls or bridges separating the 1 a core 3| in such amanner that the flat ribbon 30 serves as a spacer between consecutiveturns of the corrugated-ribbon 29. The ribbons 29 and 30 are kept inplace in-a suitable supporting frame 32.

Figure 4 shows a cell screen wherein corrugated ribbons 34 alternatingwith fiat ribbons 35 are arranged in a rectangular ,frame 36' wherebyagain a great number of cells 28 are formed.

Figure 5 illustrates another cell screen of rectagular shape havingseveral layers of corrugated or crimped ribbon 31 arranged in staggeredrelationship to one another so that the depressed parts 38 of one layerare resting directly upon the upstanding parts 39 of the layerunderneath. No fiat ribbons between the corrugated ribbon are needed inthis case.

The corrugated ribbons shown in Figures 2 and 4 are of regularlyundulated shape. Whereas in Figure 5 a different type of corrugation isused, the ribbons having relatively wide, fiat portions separated byshort, upstanding portions. The invention is, however, not limited toany particular shape of crimping or corrugating, nor is the inventionlimited to cell screens using corrugated v ribbons. For example, flatmaterial may be used throughout for forming the cells of the cellscreen, as is shown in an example in Figure 6 wherein fiat plates 41which are separated by spacing members 48, form cells 28.

If the length of the. cells 28 in the direction of the flow of the airis chosen so that the material of the plates on edge (29 and 30 inFigures 2 and 3, 34 and 35 in Figure 4, 3'! in Figure 5, and 41 inFigure 6), forming the bridges between the cells 28, has in every crosssectional plane a perimeter which is greater than the length of thelongest fibres which may be reasonably expected to be carried along bythe air stream arriving at the screen, the fibers will not be able towrap completely around those bridges. The lint fibers will be arrestedby the plates on edge in the manner indicated at 33 in Figure 3 and at49, 50 and Bi in Figure 6. That is to say, the lint fibers will eitherlie across the edges of two or more plates as shown in Figure 6 for thefiber 50, or otherwise will extend into the interior of one or two cells28 alongside of the walls thereof, as the fibers 33 in Figure 3, of thefibers 49 and 5| in Figure 6. Defined in another way, the fibers will beprevented from tangling if the length of the cells 28 in the directionof the air flow is greater than half the length of these fibers. Ipreferto use cells of a length which will take care of fibers of evenextraordinary length, although a cell screen which will safely preventtangling of fibers up to an ordinary maximum length may be regarded assatisfactory. A cell screen made of plates or ribbons having a width of1% or more will assure good results for laundry drying tumblers.

Returning now to Figure 1 and following first the air flow taking placewhen the damper 24 is 5 in the position shown in dotted lines, it willbe seen that under the action of the fan or blower l5 air entering thehousing Ill through the air inlet openings 26 will pass through therevolving cylinder 53 and the fan l5, the latter discharging the airinto a pressure chamber 40. If circulation of the air through the heaterl6 and again through the cylinder 53 is desired, the dampers 22, 23, and24 are brought into the positions shown in full lines. This establishesa communication between the pressure chamber 40 and the space 4| belowthe cell screen 25. The air following this path between the dischargeside of the fan I5 and the cell screen 25 traverses the screen in theupward direction, thus reaching a space 42 above the screen and flowingfrom there through the heater [6 and a duct 43 formed between the wallsl4 and iii of the housing ill to the upper end of the cylinder 53. Fromhere the air follows the path already described which is indicated inFig- 5 ure 1 by arrows shown in full lines, through the revolvingcylinder 53, fan l5, chamber 40, space 4|, screen 25, space 42, heaterl6 and through duct 43 back to the cylinder 53.

When it is desired to feed cold air to the tumbler, for instance to coolthe clothes in the cylinder 53 after theyhave been sufllciently dried bythe heated air repeatedly circulated through the tumbler, dampers 22, 23and 24 are moved into the positions shown by dotted lines. This opens anair path from the discharge end of the fan l5 to the cell screen 25,through space 42 above that screen. Reaching the upper side of cellscreen 25 the air passes through it in a downward direction, carryingthe lint away from the screen, reaches space 4|, and leaves the machinethrough the outlet openings 21 as indicated by the arrows shown indotted lines in Figure l.

' .This outlet 21 may be connected by a duct (not shown) to the outsideof the building.

45 It will be seen that the air must pass through the screen 25 whetherthe dampers 22, 23 are in the position shown in full lines forrecirculation of air heated by heater I6, or in the position shown indotted lines for the one-way passage of cold air. The two air pathswhich result from the two alternate positions of the dampers 22, 23, 26both pass through the screen 25 but traverse the cells of this screen inopposite directions. A has been'mentioned before,

the flow of air through the cells is upward for recirculation anddownward for the discharge ofthe air from the tumbler through the outlet21. Lint carried by the heated air arriving at the lower side of thescreen 25 during circulation is deposited on this screen. For thereasons pointed out, fibers deposited on the screen 25 are unable towrap themselves around the bridges of the cell screen. The ends of .suchfibers cannot twist together, regardless of the strength of the o5 blastof blower l5. Thus, when the dampers are shifted to the position inwhich they permit the one-way passage of cold air through the tumblerthe direction of. the air stream through the cell screen 25 is reversedas compared with the direction of the air stream through 'the cellscreen during the recirculation period of heated air. The cold airstream will be able to pick up and remove from the screen the lintpreviously deposited thereon. In this manner a really eiiectiveautomatic cleaning. of the screen at the end of each recirculationperiod is assured, leav ing the screen in perfect condition for the nextoperation of the tumbler.

In Figure 1 the cell screen is shown as located between the dischargeend of the fan l5 and the heater I6. It will be understood, however,that the screen may be arranged at some other convenient place withinthe tumbler, such as between the cylinder 53 and the fan IS in whichcase the delinting of the air is taking place before the air enters thefan.

While I have shown and described certain embodiments of the invention,it is understood that these embodiments have been given by way ofexample only and that various changes, rearrangements and modificationsmay be made without departing from the spirit of the invention or fromthe scope of the appended claims.

What I claim is:

1. In a drying tumbler, in combination, a housing having an air inletand an air outlet, a stationary delinting screen and a fan in saidhousing, means for forming two air paths alternately leading from thesame side of said fan to opposite sides of said delinting screen, saidmeans including dampers controlling said two air paths for reversing theair flow through said stationary screen, said screen comprising a seriesof adjoining walls forming cells, said walls, in orderto prevent thelint fibers arriving at the screen from wrapping completely around theelements of the screen, consisting of closely spaced plates facing theair stream with their edges and extending over a substantial length inthe direction of said air stream.

2. In a drying tumbler, in combination, a housing having an air inletand an air outlet, a stationary delinting screen and a fan in saidhousing, means for forming two air paths alternately leading from thesame side of said fan to opposite sides of said delinting screen, saidmeans including dampers controlling said two air paths for reversing theair flow through said stationary screen, said screen comprising a seriesof ad- Joining walls forming cells, said walls, in order to prevent thelint fibers arriving at the screen from wrapping completely around theelements of the screen, being of a length in the direction of the airstream many times greater than the thickness of said walls,

3. In a drying tumbler, in combination, a housing having an air inletand an air outlet, a stationary delinting screen and a fan in saidhousing, means for forming two air paths alternately connectable to thesame side of said fan to opposite sides of said delinting screen, saidmeans including dampers controlling said two air paths for reversing theair flow through said stationary screen, said screen comprising a seriesof ad- Joining cells, formed at least partly by adjacent layers ofcorrugated ribbon facing the air stream with its edges.

4. In a machine for drying clothes or the kind in which each batch ofclothes is subjected first to heated air recirculating repeatedlythrough tion and the air passing. to the atmosphere through the samepassage in the other direction, a stationary delinting screen in thepassage, said delinting screen having plates extending in the directionof the air stream over a substantial length whereby the lint depositedduring recirculation on the screen is automatically removed during theperiod when the dried clothes are cooled by air flowing to theatmosphere, an air path for the flow in one direction of therecirculating air, a second air path for the flow in the oppositedirection of the air that is not recirculated, said stationary delintingscreen intercepting both said air paths, dampers controlling said twoairpaths for reversing the air flow through said screen, in which screenthe lint is caught on the edges of said plates during the period ofrecirculation, and is automatically blown off when the air current isreversed.

5. In a drying tumbler, in combination, a housing having an air inletand an air outlet, 8. stationary delinting screen and a fan in saidhousing, means for forming two air paths alternately leading from thesame side of said fan to opposite sides of said delinting screen, saidmeans including dampers controlling said two air paths for reversing theair flow through said stationary screen, said screen comprising a seriesof adjoining cells formed by several layers of corrugated ribbon facingthe air stream with their edges, the corrugations in, said layers beingarranged in staggered relationship to those in adjacent layers sothatthe depressed parts of one layer rest directly upon upstanding parts ofan adjacent layer.

ARCHIBALD H. DAVIS, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PA'I'ENTS France May 3, 1932

